body {
    margin: 0;
}

blockquote, body, button, code, dd, div, dl, dt, fieldset, form, h1, h2, h3, h4, h5, h6, input, legend, li, ol, p, pre, strong, td, textarea, th, ul {
    padding: 0;
    margin: 0;
    font-family: "Helvetica Neue", Helvetica, "Microsoft YaHei", Arial, sans-serif;
}

ol, ul {
    margin: 0;
    padding: 0;
    list-style: none;
}

li {
    list-style: none;
}

.video-box {
    width: 100%;
    height: auto;
    min-height: 100vh;

    display: flex;
    overflow: hidden;
    background: #000;
    position: relative;
}

.video-left {
    flex: 1;
    position: relative;
}

.nav-bar {
    align-items: center;
    position: relative;
    z-index: 10;
}

.video-box .nav-bar .column {
    width: 359px;
    height: 100%;
    z-index: 10;
    background: #282828;
    animation: articlemove-21040e04 .12s ease;
    display: flex;
    flex-direction: column;
}

.video-box .nav-bar .column .section-name {
    width: 100%;
    padding: 30px 18px 18px;
}

.video-box .nav-bar .column .section-name .name {
    width: 100%;
    font-size: 18px;
    color: #fff;
}

.video-box .nav-bar .column .section-name .num {
    width: 100%;
    font-size: 14px;
    color: #9d9d9d;
    margin-top: 3px;
}

.video-box .nav-bar .column .section-name div {
    display: flex;
    align-items: center;
    margin-top: 10px;
}

.video-box .nav-bar .column .section-name div .item {
    font-size: 14px;
    color: #d0d0d0;
    text-overflow: ellipsis;
    overflow: hidden;
    white-space: nowrap;
}

.video-box .nav-bar .column .section-name div .item:nth-child(n+2) {
    margin-left: 20px;
}

.video-box .nav-bar .column .section-name div a {
    cursor: pointer;
    color: #d0d0d0;
}

.video-box .nav-bar .column .section-name div a:hover {
    color: #f5a623
}

.video-box .nav-bar .column .switch-list {
    width: 100%;
    height: 48px;
    line-height: 48px;
    padding-left: 18px;
    display: flex;
    align-items: center;
    background: #333;
}

.video-box .nav-bar .column .switch-list span {
    cursor: pointer;
    display: flex;
    align-items: center;
    font-size: 16px;
    color: #d0d0d0;
    position: relative;
}

.video-box .nav-bar .column .switch-list .active-tab {
    color: #e9e9e9;
    font-size: 16px;
    border-bottom: 2px solid #f5a623;
    z-index: 5;
}


.video-box .nav-bar .column .chapter-box {
    height: calc(100vh - 175px);
    overflow-x: hidden;
    overflow-y: scroll;
}

::-webkit-scrollbar {
    width: 6px;
    height: auto;
    background-color: #f5a623
}

::-webkit-scrollbar-track {
    background: #282828;
    background-color: #282828;
    -webkit-box-shadow: inset 0 0 6px rgba(0, 0, 0, .3)
}

::-webkit-scrollbar-thumb {
    border-radius: 29px;
    background-color: #f5a623;
    -webkit-box-shadow: inset 0 0 6px rgba(0, 0, 0, .3)
}


.video-box .nav-bar .column .chapter-box .chapter {
    list-style: none;
    height: auto;
    position: relative;
}

.video-box .nav-bar .column .chapter-box .chapter ul > a {
    text-decoration: none;
}

.video-box .nav-bar .column .chapter-box .chapter-title {
    height: 50px;
    line-height: 50px;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
    padding: 0 18px;
    position: relative;
    font-size: 14px;
    color: #e9e9e9;
    letter-spacing: .23px;
}

.video-box .nav-bar .column .chapter-box .section {
    height: 36px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    font-size: 14px;
    color: #9b9b9b;
    position: relative;
    cursor: pointer;
    padding: 0 18px;
}

.video-box .nav-bar .column .chapter-box .section:hover {
    color: #fff !important;
    background: #333
}

.video-box .nav-bar .column .chapter-box .section section {
    display: flex;
    align-items: center;
}

.video-box .nav-bar .column .chapter-box .section .status {
    width: 12px;
    height: 12px;
    border-radius: 50%;
    border: 1px solid #525456;
    margin-left: 5px;
    line-height: 12px;
    display: flex;
    align-items: center;
    justify-content: space-around;
}

.video-box .nav-bar .column .chapter-box .section:hover .status {
    background: transparent;
    border: 1px solid #fff
}

.video-box .nav-bar .column .chapter-box .section .status .played {
    width: 8px;
    height: 8px;
    background: #f5a623;
    border-radius: 50%;
    transform: scale(.8);
}

.video-box .nav-bar .column .chapter-box .section .section-number {
    width: 200px;
    height: 36px;
    line-height: 36px;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
    margin-left: 8px;
    margin-right: 30px;
    font-size: 12px;
    letter-spacing: .19px;
}

.video-box .nav-bar .column .chapter-box .section section {
    display: flex;
    align-items: center;
}

.video-box .nav-bar .column .chapter-box .section .section-time {
    width: 40px;
    font-size: 12px;
    letter-spacing: .123px;
    white-space: nowrap;
    text-overflow: ellipsis;
    overflow: hidden;
}

.video-box .nav-bar .column .chapter-box .section img {
    width: 10px;
    height: 10px;
    border: 0;
    vertical-align: middle;
}

.video-box .video-left .section-number {
    width: 100%;
    height: 70px;
    margin: 0 auto;
    padding-left: 20px;
    color: #fff;
    background: #333;
    z-index: 2;
    position: relative;
    display: flex;
    align-items: center;
    justify-content: center;
}

.video-box .video-left .section-number .back {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 70px;
    height: 24px;
    color: #fff;
    background: #a0a2a8;
    border-radius: 0 2px 2px 0;
    font-size: 14px;
    position: absolute;
    left: 0;
    top: 10px;
    cursor: pointer;
}

.video-box .video-left .section-number .back img {
    width: 8px;
    height: auto;
    margin-right: 8px;
}

.video-box .video-left .section-number h1 {
    color: #fff;
    font-size: 18px;
    font-weight: 400;
}

.video-box .video-left .play-box {
    height: calc(100vh - 70px);
}